Process for the improved winterization of oil



United States Patent 3,360,533 PROCESS FOR THE IMPROVED WINTERIZATION OFOIL James C. Wootton, Springfield Township, Hamilton County, and FredricJ. Bani, Cincinnati, Ohio, assignors to The Procter & Gamble Company,Cincinnati, Ohio, a corporation of Ohio No Drawing. Original applicationJune 17, 1963, Ser. No. 288,438, now Patent No. 3,290,340, dated Dec. 6,1966. Divided and this application May 17, 1966, Ser. No.

4 Claims. (Cl. 260-428) ABSTRACT OF THE DISCLOSURE Process to improvethe ease of obtaining, and increas- 'ing the yields of winterized oilsby adding a crystal modifier such as 1-palmitoyl-2,3-(p-carbethoxypropionin) to the oil to be winterized.

This is a divisional application of US. Patent 3,290,- 340, Dec. 6,1966.

This invention relates to novel derivatives of glycerol, and moreparticularly, it relates to substances in which glycerol is esterifiedwith a monoester of succinic acid.

One of the most common glycerol derivatives is ordinary animal andvegetable fat which consists essentially of the tri-ester of glycerol inwhich all three hydroxy groups are esterified with saturated and/orunsaturated fatty acids. Such fatty acids range generally in chainlength from about 8 to about 24 carbon atoms. These tri esters, or fats,are naturally-occurring substances.

Other tri-esters of glycerol occur in nature. Examples of these are thephosphatides. In these compounds the glycerol is esterified with fattyacids and also with phosphoric acid. Examples of this class of materialsare lecithin, in which the phosphoric acid is further esterified withcholine, and cephalin, in which the phosphoric acid is similarlyesterified with hydroxyethylamine.

In recent times partial and tri-esters of glycerol have beensynthesized. Some of these synthetic materials are widely used for theirsurface active properties in applications such as emulsification.Examples of partial esters of glycerol are the monoand diglycerides,which are so effective in permitting the incorporation of large amountsof sugar in commercial bakery cake recipes.

Other applications involve the esters of acetic acid to form acetylatedglycerides, or acetin fats, and of lactic acid to form emulsifiersuseful in prepared culinary mixes. It is an object of this invention tofurnish new glycerol esters prepared from succinic acid monoesters.

It is a further object of the present invention to prepare substanceswhich improve the filterability of win terized oils. Yet another objectof the instant invention is to provide substances useful ascrystallization inhibitors which present invention will become apparentto those skilled in the art after they have read and become familiarwith this disclosure.

The novel compositions of matter contemplated by the instant inventionare defined by the formula I EEC-O C O CHBCH CO 0R wherein R is analkanoyloxy group containing from 12 to 20 carbon atoms and R and R areeach alkyl groups ice having from one to three carbon atoms in themolecule.

The fatty acid moiety used in the practice of this invention, that is, Rmay be derived from any saturated fatty acid having from 12 to 20 carbonatoms; it may also be obtained from mixtures of saturated fatty acidsand from fatty acids derived from substantially completely hydrogenatedoils and fats which predominantly contain fatty acids having from about12 to about 20 carbon atoms.

As used herein, the term mono-ester indicates that the dicarboxylicacid, succinic acid, has formed an ester with only one of the twocarboxylic acid groups. A triester of glycerol is one in which all threeof the hydroxyl groups have formed an ester linkage with acid, while a(ii-ester is one in which only two of the three possible hydroxyl groupshave formed an ester linkage with acid. Such partial esters of glycerolwith one or two of the hydroxyl groups esterified with a fatty acid arealso known as monoglycerides and diglycerides, respectively.

For convenience in describing the preparation of the novel substances ofthis invention, the succinic acid monoester with an alkyl alcohol may bereferred to as B-carbalkoxypropionic acid or its derivatives. Forexample, the mono-ester of ethyl alcohol would be referred to as,B-carbethoxy propionic acid. In referring to the substances of thisinvention as described in the above structural formula, they will bedesignated as the fatty acid derivative of 2,3-di(fl-carbalkoxypropionin). Thus a derivative of palmitic acid would be characterized1-pal mitoyl-2,3-di B-carbalkoxy propionin) The compounds of thisinvention can be synthesized by a number of reaction routes. One methodwhich has been found convenient involves the reaction of one mole of thefatty acid monoglyceride with at least two moles ofB-carbalkoxypropionyl chloride in the presence of pyridine usingchloroform as the solvent. The reaction mixture is permitted to standfor about two days, or

.until the reaction is complete; said mixture is dissolved in ethylether; and the by-products are removed by washing, first with water andthen with dilute sulfuric acid, dilute sodium hydroxide, and water. Thesolvent is subsequently removed by evaporation. If desired, this productcan be purified by crystallization from petroleum ether andhexane-ethanol. The preparation of l-palmitoyl-2,3-di(fl-carbethoxypropionin) by this method is set forth in Example 1 below.

Another route which may be used is to prepare the compound byesterifying 1,Z-di-B-carbalkoxypropionin with palmitoyl chloride. Othermethods will suggest themselves to those skilled in the art, but thefirst route discussed above is preferred.

The preparation of the substances of this invention is exemplifiedbelow.

Example I Three hundred grams (three moles) of succinic anhydride and210 ml. of absolute ethanol were heated on the steam bath for two hoursand then distilled. Three hundred and forty-seven grames (79% yield) ofmaterial boiling at 94-97910. -(at a pressure of 0.2-0.3 mm. of mercury)were collected. This material possessed an acid value of 384 andasaponification value of 768 which cor responds to the theoreticalfigures required for ethyl hydrogen succinate (the mono-ester). Threehundred and forty grams (2.86 moleslof thionyl chloride were added tothe 347 grams (2.48 moles) of ethyl hydrogen succinate and the solutionwas heated on the steam bath for six hours. Excess thionyl chloride wasdistilled off and the residue was vacuum distilled. The yield ofB-carbethoxypropionyl chloride was 847 grams (92%), b.p. 102 103 C. (ata Calcd. for

had been previously water-washed and dried over sodium sulfate. Onehundred and sixty-six grams (1.01 moles) of fl-carbethoxypropionylchloride were added slowly to the solution while the solution was beingagitated. The reaction mixture was maintained at room temperture bycooling the reaction vessel in ice as necessary. After standing for twodays at room temperature, the solution was diluted -with ethyl ether andwashed successively with water, a

% aqueous solution of sulfuric acid, a 5% aqueous solution ofsodiumhydroxide, and finally with water. After drying over sodiumsulfate, the solution was filtered and evaporated to yield 237 grams(98%) of product. This material was recrystallized once from six volumesof petroleum ether at 20 C. and finally from six volumes of 1:1hexane-alcohol at 0 C. The product thus obtained melted at 3840 C. andhad a saponification value of 485, the theoretical saponification valueof 1-palmitoyl-2,3,-di (B-carbethoxypropionin) being 478.

Corresponding methyl, propyl and iso-propyl derivatives are obtained bysubstituting equimolar quantities of methanol, propanol, and isopropanolfor ethanol in the above example. A mixture of any or all of thealcohols could be used or a single alcohol could be used. In lieu of thepalmitic monoglyceride, monoglycerides of lauric, myristic, stearic, andarachidic acids, or mixtures of any or all of these acids could be used.Additionally, monoglyceride prepared from substantially completelyhydrogenated naturally-occurring fats, such as coconut, corn,

cottonseed, olive, palm, peanut, safflower, sesame, and soybean, oils orfats such as lard, beef tallow, and mutton tallow, could be used toprepare the monoglyceride.

The compounds of this invention are useful, among other things, ascrystal modifiers, as in the preparation of winterized oils by chillingand filtration; as crystal inhibi tors, for example, improving the chilltest in salad oils; and as suds-depressing agents for use in low-sudsingdetergent compositions.

Examples of a few uses of these compounds are below exemplified with1-palmitoyl-2,3-di-( 3-carbethoxypropi0- nin).

Example 2 One hundred grams of directed-interesterified soybean oil wasmaintained at 32 F. until crystallization equilibrium was reached. Thisoil acted as a blank for comparison. To another 100 g. sample of thesame rearranged soybean oil was added 0.4 g. of the1-palmitoyl-2,3-di-(,B-carbethoxypropionin) prepared in Example 1. Thisoil also was maintained at 32 F. for a like period to attaincrystallization equilibrium.

The two samples of oil were filtered through filter paper in a Buchnerfunnel, using a vacuum to aid the fluid flow. The ease of filtration wasjudged by noting the time required for the rate of filtration to slow tothe rate of one drop in each seconds. The yields of the crystallized andliquid fractions were recorded. The results are 1 Liquid fraction.

It can be seen from the foregoing data that the requisite filtration wasaccomplished in less than one third of the time on the soybean oilcontaining 0.4 g. of the 1-palmitoyl-2,3-di-(B-carbethoxypropionin), andthe yield of the desired winterized oil (liquid fraction) was about 7%greater.

The foregoing example demonstrates the use of the compounds of thisinven ion as crystal modifiers to improve the ease of obtaining andyields of winterized oils. The glycerol derivatives of this inventionare effective crystal modifier-s when used in amounts from about 0.05 to1.0 percent of the weight of the oil. The preferred range of usage ofthese compounds as crystal modifiers is from about 0.2 to about 0.6percent by weight of the oil.

Entirely comparable results can be obtained when the novel compositionsof matter of this invention are used as crystal modifiers in the processof Winterizing cottonseed, soybean, corn, sunflower, olive, and peanutoils. Like results are also obtained on the oils just mentioned whensaid oils are rearranged or lightly hydrogenated and then winterized.

The process of winterization as used herein comprises the steps ofchilling a liquid oil to a temperature substantially below 70 '1permitting the chilled oil to remain at that temperature untilcrystallization equilibrium has been obtained, and separating, as byfiltration, the resultant mixture of crystals and oil to obtain acrystal fraction and a liquid oil fraction. The liquid oil fraction isthen stable against crystal formation to temperatures at least as low asthose to which it was subjected during winterization. The termcrystallization equilibrium is used herein to indicate that anequilibrium had been reached between the solid phase (crystals) and theliquid phase of the oil.

In general, winterization can be applied to any glyceride oil. Theprocess is generally used commercially only for cottonseed oil and forthat and other vegetable oils which have been lightly hydrogenated orrearranged, either in a random or directed manner.

To exemplify the crystal inhibiting characteristics of the novelcompositions of this invention, l-palmitoyl-2,3-di(p-carbethoxypropionin) was added to winterized cottonseed oil at levelsof 0.1 and 1%. When the resulting mixture was stored at 32 F. andobserved for the formation of crystals, the compound of this inventionwas found to be as effective a crystallization inhibitor in salad oilsas oxystearin, a well-known crystallization inhibitor food additive.

The compositions of this invention were found to be very good withrespect to heat stability and when used in a standard smoke point testat the 5% level was found to have a smoke point of 390 F. Thesesubstances were further found to reduce the Solids Content Index offats, such reduction apparently being due to solubilization of theglycerides.

The invention having been described, what is claimed is:

1. In the process of Winterizing oil comprising the steps of chilling aliquid oil to a temperature substantially below 70 F, permitting thechilled oil to remain at that temperature until crystallizationequilibrium has been obtained, and separating the resultant mixture ofcrystals and oil to obtain a crystal fraction and a liquid oil fraction,the improvement which consists of adding to the oil a composition ofmatter having the formula.

HC-OOOCH CH COOR;

H3CO O 0 CHQSCHZC 0 OR; wherein R is an alkanoyloxy group containingfrom 12 to 20 carbon atoms, and R and R are alkyl groups containing fromone to three carbon atoms in the molecule in an amount of from about0.05 to about 1.0% by weight of oil to be winterized.

2. The process of claim 1 in which the amount of said com-position addedis from about 0.2 to about 0.6% by weight of the oil to be winterized.

in an amount of from about 0.2 to about 0.6% by weight of the oil to 'bewinterized.

No references cited.

5 HENRY R. JI-LES, Primary Examiner.

A. M. TIGHE, Assistant Examiner.

1. IN THE PROCESS OF WINTERIZING OIL COMPRISING THE STEPS OF CHILLING ALIQUID OIL TO A TEMPERATURE SUBSTANTIALLY BELOW 70*F., PERMITTING THECHILLED OIL TO REMAIN AT THAT TEMPERATURE UNTIL CRYSTALLIZATIONEQUILIBRIUM HAS BEEN OBTAINED, AND SEPARATING THE RESULTANT MIXTURE OFCRYSTALS AND OIL TO OBTAIN A CRYSTAL FRACTION AND A LIQUID OIL FRACTION,THE IMPROVEMENT WHICH CONSISTS OF ADDING TO THE OIL A COMPOSITION OFMATTER HAVING THE FORMULAR2-OOC-CH2-CH2-COO-CH(-CH2-R1)-CH2-OOC-CH2-CH2-COO-R3 WHEREIN R1 IS ANALKANOYLOXY GROUP CONTAINING FROM 12 TO 20 CARBON ATOMS, AND R2 AND R3ARE ALKYL GROUP CONTAINING FROM ONE TO THREE CARBON ATOMS IN THEMOLECULE IN AN AMOUNT OF FROM ABOUT 0.05 TO ABOUT 1.0% BY WEIGHT OF OILTO BE WINTERIZED.